Various publications, including patents, published patent applications, technical articles, and scholarly articles, are cited throughout the specification. Each of these cited publications is incorporated by reference in this document, in its entirety and for all purposes.
Fluorescent molecular tomography (FMT) is an imaging technique that allows for fluorescence-based imaging of the inside of live animals. Fluorescence measurements are obtained, and the three-dimensional distribution of fluorescent agents is reconstructed. FMT is quantitative and allows for measurements of fluorophore intensity, e.g., marker concentration, at locations within the animal. FMT is limited, however, insofar as it lacks the ability to generate precise anatomical details of fluorescent tissue and the surrounding tissue.
Magnetic resonance imaging (MRI), in contrast to FMT, is able to provide high resolution three dimensional images of anatomical structures. Magnetic resonance imaging is limited, however, insofar as it lacks fluorescent probe detection sensitivity. Therefore, it is desirable to combine FMT and MRI to achieve detailed images of fluorescence-labeled tissue in the proper anatomical context. Combined FMT and MRI imaging is valuable as a research and diagnostic tool, particularly in the area of oncology (McCann C M et al. (2009) Neuroimage 45:360-9).
As FMT and MRI are separate techniques carried out using separate machines, image alignment from both analyses is not straight forward. The incompatibility of platforms to hold animals in place during imaging with each technique is a primary contributor to the problems of image alignment. Incompatibility necessitates that an animal be imaged using FMT on one platform, and then moved to another platform for MRI imaging. It is difficult and time consuming to realign the animal in the same position and orientation between the FMT and MRI platforms. In addition, movement of the animal may cause shifting of internal organs, further contributing to alignment difficulties. A need exists to reduce or avoid the requirement to move the animal, and to enhance the efficiency and accuracy of FMT-MRI image alignment.